What is EID?

Electron Induced Dissociation (EID)

Electron Induced dissociation (EID) is a method for fragmenting molecules species in mass spectrometry induced by interaction with (free) electrons (electron-induced dissociation, EID) at electron energies ranging from near 0 to >30 eV. The product-ion mass spectra exhibited EID originating from electronically excited even-electron precursor ions reduced radical cations formed by capture of low-energy electrons, and oxidized radical cations produced by interaction with high-energy electrons. Investigators have demonstrated that the spectra produced from high-energy EID EMS cell exhibit essentially the same qualitative structural information, i.e., amino acid side-chain (SC) losses and backbone cleavages, as observed with a Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. EMS cells incorporated into mass spectrometers could make tandem high-energy EID mass spectrometry more widely accessible for analysis of peptides, small singly charged molecules, pharmaceuticals, and clinical samples, if some of the inefficiencies can be overcome.